Preheated-air feeder for fire pots



Nov. 23,1926. I 1,607,692

' N. J. RUSSELL PREHEATED AIR FEEDER FOR FIRE POTS Filed June 23, 1925 .d Nov. 23, E926,

UNITED STATES PATENT QFFICE.

PREI-IEATED-AIR FEEDER FOR FIRE POTS.

Application filed June 23, 1925. Serial No. 39,018.

My invention pertains to an improved preheated air feeder for fire pots, and has for its main object to provide improved means for preheating air and for feeding 6 said air to the top of'the burning fuel in the fire pot, thereby providing complete combustion of the fuel and of the gases at the top of the fire pot. provide such a preheater and air feeder m which includes a hood constructed of high heat resisting material such as is used for making furnace linings and the like. And another object is to provide such a device including a covering hood and an inner member therein arranged to form an annular air heating space with said hood, which space is narrower at the top than at the bottom, thus to force heated air at the top of said space with increased speed through the upper outlets in the hood. Other objects and advantageous ends are accomplished with my invention, as will become apparent from the following description, taken in connection with the accompanying drawing, in which Fig. 1 is a partial elevational view of the boiler, showing my invention mounted in position in the fire pot therein;

Fig. 2 is an enlarged vertical sectional view of the complete invention, taken on line 22 of Fig. 1; and

Fig. 3 is a horizontal crosssectional view, taken on line 3-3 of Fig. 2.

The preferred form of construction, as illustrated in the drawing, comprises an outer covering member or hood 6 provided with air outlets or air openings 7, around its upper circumference adjacent the closed upper end 8. This hood may be made broader at its lower open end if desired, and the hood is mounted with such open end directly on'the grate 9 of the boiler 10 and within the fuel 11 in the fire pot. The

hood is arranged sufliciently high to have its top 8 with the outlet openings 7 extending above the top or head of the fuel 11 in the fire pot, as indicated in Fig. 1, and these openings are arranged to conduct or direct the heated air laterally from the hood into the gases existing over the burning fuel, thus thoroughly commingling with such ases.

a The hood is constructed of excellent fire proof material, preferably such as is used Another object is to in making furnace linings, etc., or as used in places where great heat has to be resisted; and this hood is therefore adapted to resist extremely high temperatures preva lent in fire pots. The hood rests directly on the grate in the fuel, and requires no base.

I may also provide a conduit or inner tu bular member 12, provided with spacing fingers 13, to support the conduit onthe grate, and to space it centrally in the hood, the spacing fingers being preferably made integral with said conduit. This conduit is preferably made wider at the. top than at the bottom and provides a central air channel within the conduit, which is likewise broader at the top than at the bottom, and the conduit with said hood also provide an annular air space or channel which is narrower at the top than at the bottom, as best seen in Fig. 2, thus forcing the air, which passes through the grate and through this intermediate annular channel, with greatly increased speed at the top of the channel, thereby increasing the pressure of the heated air as it issues from the outlets 7 laterally and mingles with the gases over the burning fuel. At the same time the air coming up through the central passage or channel within conduit 12 presses upward and provides additional pressure to force the hot air from the annular space still more rapidly out through the outlets 7.

The device also has the effect of moving heat Waves downward from the heated air existing in the central channel and in the annular channel, thereby preheating the air within the ash pot below the grate, and thus providing preheated air for the lower part of the entire coal bed.

The entire device is very simple and durable in construction and can be manufac tured at a little cost and it provides excel.- lent results with a considerable saving in the amount of fuel used, and also reduces smoke to a minimum.

What I claim as my invention and desire to secure by Letters Patent is:

1. In combination with a fire pot and a grate therein, a covering hood of fireproof material mountable on said grate and having outlet openings to transmit air therethrough, and a conduit detachably mounted in said hood and providing an airspace therewith conducting air upwardly through said space to said outlet openings, and to conduct preheated air downwardly from the interior of said conduitto beneath said grate.

2. In combination with a grate, a covering hood adapted to be mounted on said grate having openings around its upper end, and a conduit mounted on said grate within said hood and therewith providing an annular air space which is narrower at the top than at the bottom.

3. In combination with a grate, a covering hood adapted to be mounted on said grate and having outlet openings around its circumference adjacent its upper closed end, and a conduit mounted on said grate within said hood and being broader at its top than at its bottom and providing an inner air passage and also an annular air passage between it and said hood, said annular passage being narrower at its upper end to conduct air with increased speed to said outlet openings.

4;. In combination with a grate, a covering hood mountable on said grate within the lire pot and having air outlets near the upper end, and a conduit provided with spacing lingers mounted in said hood and providing an annular air space therewith.

5. In combination with a grate, a covering menses hood having its open bottom end resting dircctly on said grate within a fire pot and having air openings around its upper closed end, a conduit in said hood and mounted directly on said grate and having its upper end wider than its bottom, said construction providing a central air space within said conduit and also an annular air space between said conduit and hood which is narrower at the top than at the bottom to increase the speed of air at said top as it issues through said air openings.

6. In con'ibination With a grate, a covering hood of the proof material arranged to be mounted with its open end directly on said grate in a fire pot and having outlet openings adjacent its closed top, and a conduit mounted in said hood directly upon the grate and having spacing lingers for holding it centrally within the hood, said conduit and hood forming an annular channel which is narrower at the top than at the bottom to increase the speed oi the air at the top and as it passes through said outlet openings.

In testimony whereof I have signed my name to this specification.

NELSON J. RUSSELL. 

